US president Joe Biden and his predecessor Donald trump on Wednesday secured nominations as presidential candidates for the elections later this year, setting up a rematch between the rivals after four years.

Both Mr Biden and Mr Trump, who had already disposed of their primary challengers, secured enough delegates in the states of Mississippi, Washington and Georgia to push them over the threshold needed to become their parties’ nominees in the November election.

To choose a presidential nominee, an indirect election or primary is held where voters decide the number of delegates each party convention receives and these delegates in turn select the party’s presidential nominee. In primaries, candidates need a majority of delegate votes at the convention to win the party’s presidential nomination.